Rotating repeated Image Texture/ Tile a Texture in 90° increments
A possible node settings:

Use a &quot;vector rotate&quot; node with UV as input and a random rotation around z.
The random rotation is given by picking one random value per tile:

Take the floor part of the UV (so one value per tile)
Use a white noise to get a random value between 0 and 1
Multiply by 4 as we want 4 cases: 0, 90, 180, 270°
Take the floor of that to be aligned to the integer values
Multiply by pi/2 to obtain the rotation in radians